CuS and Cu_1.8S have been investigated respectively as anodes of lithium-ion batteries because of their abundant resources, no environment pollution, good electrical conductivity, and a stable discharge voltage plateau. In this work, CuS/Cu_1.8S nanocomposites were firstly prepared simultaneously by the one-pot synthesis method at a relatively higher reaction temperature 200 °C. The CuS/Cu_1.8S nanocomposites anodes exhibited a high initial discharge capacity, an excellent reversible rate capability, and remarkable cycle stability at a high current density, which could be due to the nano-size of the CuS/Cu_1.8S nanocomposites and the assistance of Cu_1.8S. The high electrochemical performance of the CuS/Cu_1.8S nanocomposites indicated that the Cu_xS nanomaterials will be a potential lithium-ion battery anode.

Cobalt oxides have been intensely explored as anodes of lithium-ion batteries to resolve the intrinsic disadvantages of low electrical conductivity and volume change. However, as a precursor of preparing cobalt oxides, Co(OH)₂ has rarely been investigated as the anode material of lithium-ion batteries, perhaps because of the complexity of hydroxides. Hybridized Co(OH)₂ nanomaterial structures were synthesized by the water bath method and exhibited high electrochemical performance. The initial discharge and charge capacities were 1703.2 and 1262.9 mAh/g at 200 mA/g, respectively. The reversible capacity was 1050 mAh/g after 150 cycles. The reversible capability was 1015 mAh/g at 800 mA/g and increased to 1630 mAh/g when driven back to 100 mA/g. The electrochemical reaction kinetics study shows that the lithium-ion diffusion-controlled contribution is dominant in the energy storage mechanism. The superior electrochemical performance could result from the water bath method and the hybridization of nanosheets and nanoparticles structures. These hybridized Co(OH)₂ nanomaterial structures with high electrochemical performance are promising anodes for lithium-ion batteries.

Transition metal chalcogenides as potential anodes for lithium-ion batteries have been widely investigated. For practical application, the drawbacks of low conductivity and volume expansion should be further overcome. Besides the two conventional methods of nanostructure design and the doping of carbon-based materials, the component hybridization of transition metal-based chalcogenides can effectively enhance the electrochemical performance owing to the synergetic effect. Hybridization could promote the advantages of each chalcogenide and suppress the disadvantages of each chalcogenide to some extent. In this review, we focus on the four different types of component hybridization and the excellent electrochemical performance that originated from hybridization. The exciting problems of hybridization and the possibility of studying structural hybridization were also discussed. The binary and ternary transition metal-based chalcogenides are more promising to be used as future anodes of lithium-ion batteries for their excellent electrochemical performance originating from the synergetic effect.

Li-rich layered oxides (LLOs) with a large specific capacity of ∼300 mAh g⁻¹ show promise for developing high-energy Li-ion batteries (LIBs). However, the thermodynamic instability of the oxygen-anionic redox couple leads to lattice oxygen loss and structural transformation, resulting in a rapid decline in voltage and capacity. In this work, we rationally engineer Li-deficient phase formation in LLOs to stabilize oxygen-anionic redox chemistry and improve structural stability. The Li-deficient and Li-rich biphasic intergrowth composite is synthesized via ion exchange from the P3/O3 intermediate mixed-phase oxides. It is found that the incorporation of the Li-deficient phase makes the movement of the O 2p non-bonding energy band toward lower energy, which further alleviates the lattice oxygen release and stabilizes the oxygen-anionic redox chemistry upon Li⁺ de-intercalation. Consequently, the cycling stability is significantly enhanced in the biphasic LLOs, retaining superior capacity/voltage retention of ∼86%/88% after 400 cycles with a low capacity decay rate of 0.034% and voltage decline of 1.06 mV per cycle. The biphasic design offers a simple and feasible strategy for regulating the oxygen-anionic redox chemistry and boosting the structural stability of high-capacity LLOs.